


Cannot Be Undone

by arrafrost



Series: Dead Before the Day is Done [2]
Category: Teen Wolf (TV)
Genre: Barebacking, Bottom Derek Hale, Consensual Possession, Demon Stiles, Demon!Stiles, Demonic Possession, M/M, Rough Sex, Scenting, Top Stiles Stilinski, Willing Possession
Language: English
Status: Completed
Published: 2013-01-29
Updated: 2013-01-29
Packaged: 2017-11-27 09:04:37
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,540
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/660208
Author URL: https://archiveofourown.org/users/arrafrost/pseuds/arrafrost
Summary: <blockquote class="userstuff">
              <p>After a week of being denied sex, Stiles and his demon are able to follow through on the promise to dominate Derek.</p>
            </blockquote>





	Cannot Be Undone

**Author's Note:**

> You all asked for more of demon!stiles and even more of you wanted more porn, especially with bottom!Derek so here you are! Enjoy :D

It happened suddenly; one moment they were kissing in the doorway of Stiles’ bedroom and the next Derek’s head was rocking back against the wall, his eyes widening with shock, and a solid weight settling between his thighs. He had been expecting it the whole day yet it took him completely off guard.

He glanced down, focusing on Stiles eyes that had glazed over to the demon’s black. The way he licked his wicked smirk, as he eyed Derek up like his favorite meal, sent chills down Derek’s spine.

He’d been anticipating this since Stiles moaned the filthy promise in bed the other night and finally the demon was following through. Derek’s feet were off the ground, the demon was on the forefront of Stiles consciousness, and it was holding him up by his shoulders, hips set squarely between Derek’s spread legs.

“You don’t know how long I’ve wanted to reciprocate this,  _sourwolf.”_  The demon purred in Derek’s ear; his voice deeper than Stiles, more threatening but in a way that made Derek growl inwardly and resist the urge to buck against him.

The demon had taken to calling him sourwolf in a tone that drove Derek mad with the need to throw him down on the ground and claim him as his own. Despite already having done that. The entire pack knew that Derek and Stiles were dating now - if you wanted to call the heavy make-outs in public dating. At the very least, Stiles reeked of Derek’s scent, he was bathed in it from the inside out and any wolf that so much as entered Beacon Hills would know Stiles belonged to Derek.

The same could be said with Derek. He was covered in Stiles scent that mingled with his own powerful scent but there was something else. It had lingered on Stiles flesh as well and the two told the pack that it was simply the smell that happened when an alpha took a mate. None of the young betas would know any better. They were new to being werewolves, in comparison to Derek who had been born that way, and Derek was their first alpha other than Peter. They wouldn’t question the dark scent of the demon that neither could manage to hide after that mind blowing sex the three of them had.

Over the past week it had begun to fade, thankfully, but that was only because they hadn’t had enough time or privacy to do anything more than lock lips. The sheriff had taken the week off, something about a stressful case that reminded him of his wife - so Stiles had speculated after having to hide the key to the liquor cabinet. Which meant they couldn’t have sex in Stiles’ house.

Sex at the Hale house with the pack present was strictly off limits. They couldn’t risk having anyone in the pack over hearing them - or more specifically the demon - nor could they see Stiles’ eyes shift to black. There would be too many questions, too much fear from the betas as to why Stiles, who had been honorary pack before he and Stiles became intimate, was possessed. That’s what Stiles assumed. It was his decision to keep this from the pack. After all, he had kept it a secret from Scott for all this time… coming out of the hell closet now would only cause further pain. In addition, the demon didn’t want publicity. He wanted a quiet life which meant appearing on the surface of Stiles skin was not something that happened often. The only reason he had come out during the night with the faeries had been to protect Stiles, Lydia and the pack. Being part of Stiles meant he cared for the people that Stiles cared for.

Despite how much they loved the betas, they had become infuriating since the pups refused to ever leave the Hale house. At one point Stiles tried to convince Derek that he could skip school so they could have sex while the rest of the pups were in class. Derek didn’t buy it. Stiles' absence would be suspicious. They had to wait and finally their patience paid off. Stiles’ father went back to work that morning. He would return some time in the evening before dark most probably, which meant they had rushed over as soon as school was let out. They had a few hours to themselves and they were not going to waste them.

“You look delicious with those red eyes,” the demon’s tongue was hot and slick in Derek’s ear, his breath cooling his wet skin when he whispered, “you should wear them more often.”

Derek growled and rocked into Stiles’ hips while the demon continued to nip and suck on his sensitive ear. He had refused to tell Stiles how incredibly sensitive they were but he figured the demon could sense the quickened heart rate and the tensing of his body whenever his ears were the center of attention.

He was still getting used to this. The whole menage a trois with a boy two years under the age limit and the demon who has been possessing him for years. Yet the demon’s presence wasn’t entirely unnatural. It was simply another darker part of Stiles, yet he was separate in a way that Derek’s wolf had never been. Derek was the wolf, the wolf was Derek. He was born that way and there was no distinction between the two parts of himself; it was all Derek’s thoughts and feelings and instincts. The demon was a part of Stiles but he was also separate. He had his own thoughts that he shared with Stiles, he had his own voice, his own eyes, his own strengths. The same went for Stiles, but you couldn’t have one without the other.

“How long have you been picturing this in your mind?” The demon started grinding his hips on Derek’s, groaning as he spoke at the physical contact they’d been denied for so long. “Has it clouded your mind for the whole week  _sourwolf_?”

Derek whined at the movement and rutted into it, submitted to it. He wasn’t being forced, he wanted this, he craved it. To feel the lack of power he had over another being, to feel Stiles and the demon dominate him.

“You’re so needy for it… for us to take you. To feel us inside you, filling you up and making you ours.” One of the demon’s hands snaked down Derek’s torso, caressing his chest and abs before landing on the belt of his jeans and tugging. “It’s driving you mad, how badly you want us to fuck you into the wall with abandon, not caring whether we bruise or break you. You want it hard, rough and fast and you’ll get it that way.”

Derek moaned, throwing his head back into the wall. He was so turned on he couldn’t believe it, and Stiles indecent mouth wasn’t helping the matter.

The demon tore at Derek’s belt, unhooking it with one hand and doing the same with his jeans. Stiles always did have long, nimble fingers. He was naked from the waist down before he could blink. The demon had moved away - one hand still holding Derek up which was something that only made Derek’s cock swell more - and yanked Derek’s pants and underwear down in one go, throwing them over his shoulder as he settled between Derek’s welcoming thighs again. His own jeans brushed against Derek’s exposed length causing him to moan and rock into the friction.

“Patience.” The demon whispered, letting his thigh press higher into Derek’s crotch and savoring the filthy sounds that spilled from the wolf’s mouth.

While he busied himself with sucking a bruise onto Derek’s neck, Stiles reached into his back pocket and pulled out the packet of lube he had stashed there when he had heard his father going to work. They wanted to be prepared, no chance of leaving Derek to so much as cross the room for supplies. They had to have him there and now.

He slicked up two of Stiles fingers and slipped them between Derek’s cheeks. The wolf gasped, his body halting in all movement to focus on the sensation. The demon teased his hole with his fingers, sliding them back and forth before circling and he didn’t allow for any penetration until Derek commanded, “More.”

The demon grinned, wide and feral, as he pushed the two digits in up to the knuckles and Derek bit back a moan deep in his throat.

“You are so hot like this.” Derek opened his eyes, unsure of when he closed them, to be greeted with Stiles’ honey brown eyes and his smile that seemed more in awe than lusting as the demon had been. “God… I’m, we’re actually going to do this. I’ve dreamt about this for a long time.”

Stiles emphasized his words with shallow thrusts of his fingers, pushing them in deeper and stretching Derek. It wasn’t painful, more of a dull, uncomfortable feeling but Derek soon adjusted and rolled his hips down onto Stiles fingers, prompting him to enter another lube covered finger. It was more of a stretch but Derek took it and let himself relax around Stiles.

“Shit… I want you so bad…” Stiles bit his lip and thrust his fingers into Derek harder than he had been, making the wolf clench around him and groan. Derek gazed back at Stiles with heavy-lidded blue eyes. There was more lust in Stiles eyes now, and there was an occasional flicker to black that could only serve to turn Derek on more; having both the demon and Stiles admiring him like that when he was desperate for Stiles to fuck him into this wall…

“Then take me.” He growled, low and threatening that he wouldn’t patiently wait around for Stiles to dominate him. If Stiles didn’t act fast, Derek was going to lose control and turn the tables on their plans. It quite possibly involved shoving the majority of Stiles books, papers and research off his desk and fucking him on top of the surface since it was closer than the bed.

The black of Stiles pupil spread out, taking over the bright amber and white shades entirely as his lips curved up into a devilish grin.

“We intend to.”

The fingers inside Derek left him all too quickly and he whined at the emptiness but it wasn’t long before Stiles’ slick member pressed between him cheeks. The demon wasted no time in pushing in but there was a flicker of gold in his eyes that prevented him from shoving in entirely until Derek snarled with a bit of mockery in his voice. “Taking it slow, demon? Didn’t you say I wanted it hard, rough and fast?”

The demon’s eyes narrowed but the mischievous, pleased grin on his face widened and Derek’s breath was knocked out of him as the demon filled him in one thrust. He wasn’t given any time to adjust to the intrusion. The demon set a hard and frantic pace that forced Derek hard against the wall and soon the wolf was stifling a howl because of the pleasurable ache.

“Ah fuck… tight.” Stiles gasped on Derek’s neck, leaving open-mouthed kisses that had a significant amount of teeth that Derek most definitely didn’t mind.

Derek groaned, angling his hips to thrust back but he couldn’t get much leverage pushed against the wall as he was. “It’s been a while…” He managed to grunt, claws digging into Stiles shoulders.

“Damn… I wanna come. Just like this.” Stiles moan was desperate and soft, a strange contrast to the brutal pace of his thrusts that barely gave Derek any chance to catch his breath.

“So soon, Stiles?” Derek teased, giving him a toothy grin. Stiles wasn’t offended at the jab at his stamina it seemed because he returned his grin with a bright smile.

Stiles’ pupils were blown wide, whether from the demon controlling their body or from the exhilarating sex they were having… Derek assumed it was a mix of the two actually.

“Trust us,” they spoke in unison, both eerie and incredibly erotic, “we’ll have plenty of stamina left for round two.”

Derek smirked. Mostly from the demon’s egotism but also because the idea turned him on more than he could believe. This demon and this boy were finding all sorts of kinks Derek had never known existed for him and he licked his lips as he leaned forward, pressing a wet kiss to Stiles’ neck.

“Come inside me.”

He felt Stiles shudder at the whispered command. Blunt nails dug into his hips, where Stiles had placed both his hands for better leverage, and with a few more hard thrusts Stiles’ orgasm pulsed through him. Derek moaned softly at the feeling of Stiles’ come filling him up and clenched around Stiles’ still hard cock.

“Told… you.” The broken gasps of Stiles’ voice brushed Derek’s cheek as his hands caressed down Derek’s thighs, all the way down to his legs which he picked up and forced to wrap around his waist. Derek pulled back to give Stiles a confused look but was greeted with a lazy grin and eyes flashing from demon to human. He wasn’t able to question the possessed teen right away because hands were suddenly gripping his ass and he was groaning, bucking into the sensation as Stiles carried him across the room.

Without pulling his cock free, Stiles sat down on the bed with Derek in his lap and laid back. He stretched his arms out, resting his head on his clasped hands and smirked up at Derek with satisfied eyes.

Derek adjusted to the new position, sitting back on Stiles’ thighs and sighing as he filled him deeper than before, which could also be attributed to the additional lube that was Stiles’ come.

“Overexert yourself?” The wolf asked with a raised brow.

Stiles chuckled, his eyes may be drooping but his voice was vibrant enough. “Oh, no worries  _sourwolf_. We have plenty of energy leftover, we just want to see you do all the work. Wanna to see you fuck yourself on us.”

“Jesus…” Derek growled, his eyes glowing red. His claws dragged down Stiles’ chest from his shoulders making the demon and Stiles moan and arch up into the harsh touch, but glared up at Derek when his claws tore free from the fabric at the end of the now ruined shirt.

“I liked that shirt, you jerk.” Stiles grumbled, reaching down to lift the tattered tee over his head and toss it across the room in the vague direction of the garbage can.

Derek took no notice, his claws teasing along Stiles abdomen, tickling the light trail of hair from his belly button to the base of his cock. It was a delightfully obscene noise that left Stiles’ lips when his claws scraped at the sensitive flesh of his inner thighs at the same time as he clenched tight around Stiles’ cock.

“Fuck!” He gasped, bucking up with a jolt and the demon growled, “Don’t  _do_ that!”

Which Derek, of course, responded by doing the exact same thing again and savoring in the way Stiles bit down on his lower lip.

Stiles, with black eyes, glared up at the smug werewolf but didn’t say anything else when Derek started to lift himself up on Stiles lap. He rose until only the head of Stiles’ cock was resting inside of him before slamming back down, taking him completely and making both of their bodies tremble from it. Derek continued to ride him at the long, slow pace he’d set and he could tell from how Stiles was gritting his teeth that he had expected this to go faster.

Except Derek wanted to take his slow, wanted to savor this moment of being dominated while having the power to control his partner. To sate the demon, he dug his claws into Stiles hip, sharp enough to evoke a guttural moan from the demon before Stiles’ eyes returned in vivid color.

“Wasn’t expecting you to like it slow so much.” Stiles huffed out on the edge of enjoying the pace and being too stubborn to tell Derek he wanted more.

Derek grinned as he sank back onto Stiles’ cock and leaned forward, placing a chaste kiss to Stiles’ lips before whispering, “Nothing wrong with drawing out a good moment.”

He felt Stiles smile against his lips and he kissed him again, deeper than the last one. Stiles responded quickly, lips pressing hard on his own and falling open when Derek’s tongue trailed along his lower lip. Stiles sucked and bit his tongue affectionately in the open mouthed kiss that left them both breathless as Derek continued to grind his hips in slow circles.

The kiss broke and Derek started lifting his hips higher to drop down on Stiles lap with a quicker pace. Stiles gasped pleasantly and Derek smiled against his cheek as he inhaled the scent of his hair. There was no question or hesitation when Stiles tilted his head and exposed his neck to Derek’s nose where he inhaled long and hard before running his flat tongue over the length of Stiles’ neck. He sucked soft bruises onto Stiles neck because they had agreed that visible hickeys were against the rules – despite how much Derek and the demon protested.

Derek rode him harder as his wet kisses trailed down Stiles chest where he sucked deeper bruises, teeth tugging at the flesh, tongue licking perspiration of the boy’s warm body and leaving his own scent behind.

Feeling Stiles body move beneath him, in attempts to speed things up probably, Derek brought his hands up to press firmly down on his chest, pushing him back onto the mattress. Stiles glowered up at him with the demon’s eyes and Derek could only grin as he increased the pressure when the demon rose against Derek’s hands. He held him down as he slammed his hips down onto Stiles lap, hard and brutal just as the form beneath him desired.

They both got lost in the rise and fall of Derek’s hips and Stiles could tell by the way his claws were digging harder into his flesh that Derek was getting close. Stiles reached up and was glad Derek was too busy clawing up his chest to bat his hand away as it wrapped around Derek’s aching cock. The wolf groaned, biting his lip with his fangs that had extended and stared down at his lover with glowing red eyes. He couldn’t help thrusting up into Stiles grip after slamming himself down onto the younger’s cock.

Neither wanted it to end but they didn’t to slow down either. It took only a few more quick strokes for Derek to come over Stiles’ hand, stomach and chest. He howled and Stiles moaned as Derek’s ass tensed around him. Stiles continued to milk Derek’s orgasm for all it was worth as he started thrusting into Derek, now that he wasn’t forced to be still.

It was Derek’s exhausted, lustful voice that tipped him over the edge, “Come for me.” Which Stiles did, his back arched as he shouted and filled Derek’s ass with his come for the second time. He fell back against the bed, breathing harshly as Derek lifted himself off Stiles hips and rolled over next to him on the bed, come dripping down his thighs. Stiles didn’t fight as Derek pulled him up closer. Instead he rested his head on Derek’s chest and let his fingers trace random patterns over his hot skin.

“Are you always going to come when I tell you?”

Stiles smiled at Derek’s playfulness but answered the question seriously, “If you want.”

Derek kissed his forehead and Stiles nuzzled closer. That would certainly be something to test during the next time they had sex… which sadly wouldn’t be tonight because the sheriff would be home soon.

They lay there with only the sound of each other’s heartbeats and shallow breaths for some time before Stiles broke the silence, his pensive tone making Derek turn his head to listen. “Derek?”

“Yeah?”

“Are we… are we your mate?”

Derek paused, licking his lips as he contemplated the question. If it had only been Stiles, there would have been no hesitation, no need to think about the complications of their relationship. But that wasn’t the case. There was a demon inside Stiles and demons were inherently evil, disloyal, terrible creatures. This one… this one was different. He was fiercely loyal to Stiles, protective of him to the point where he often convinced Stiles to stay away from danger when he wouldn’t even listen to Scott or Derek, and he gave Stiles the most control of their shared body, acted as a guest… which was technically what he was. Now, Derek was beginning to notice the loyal possessiveness, and even affection, that the demon gave to Stiles was being extended to Derek. He was opening up, allowing himself to be vulnerable and almost… human in a way.

Derek startled when he noticed that Stiles had tilted his head to gaze up, widened pupils begging for an answer.

Derek smiled softly, confidently, “Yes, you are.”

**Author's Note:**

> More fanfiction on my [tumblr](http://arrafrost.tumblr.com/masterpost) :D


End file.
